Production of polymerization products from isobutylene



Patented Mar. 14, 1944 PRODUCTION OF POLYMERIZATION PRODUCTS FROM ISOBUTYLENE Michael Otto, Ludwigshaien-on-the-Rhlne, Germany; vested in the Alien Property Custodian No Drawing. Application May 23, 1939, Serial No.

275,323. In Germany May 24, 1938 8 Claims.

The present invention relates to improvements in the production of polymerization products from isobutylene either alone or in mixture with diolefines. I

It is already known that high molecular weight polymerization products are obtained when isobutylene is polymerized with the aid of catalysts ,of the Friedel-Crafts reaction, as for example aluminum chloride or-bromide, iron chloride, tin chloride, titanium chloride or preferably boron fluoride, at temperatures below 10 below zero C. The molecular weight of the polymerization products is greater the lower the temperature during the polymerization and the purer the initial material. For example, if pure liquid isohutylene be polymerized in the presence of a liquid diluent, such as for instance propane, with the aid of boron fluoride at 80 below zero 0., polymerization productsare obtained having an average molecular weight of about 70,000. Oh the other hand, by working at 103 below zero C., the products obtained have molecular weights of 150,000 to 200,000 or more. If, however, the isobutylene is not quite pure but contains for example unsaturated hydrocarbons, such as for instance propylene, normal-butylene, amylene, hexylene or octylene, or also ketones, aldehydes, ethers or esters, there are formed at the same temperatures polymerization products of considerably lower molecular weight, aslfor example at 103 below zero C. a product of which the molecular weight amounts to only from about 10,000 to 15,000.

I have now found that the course of the polymerization of isobutylene is favorably influenced by working in the presence of small amounts of substances which are soluble in the reaction mixture under the working conditions and which further have the property of beingeapable oi dissolving boron fluoride and which with boron fluoride either form double compounds or hydrolizes the same with the intermediate formation of hydrogen fluoride. The favourable action of these substances is evident, however, not only when working with boron fluoride as the catalyst but also when employing other catalysts of the Friedel-Crafts reaction, as for example aluminum chloride or bromide, iron chloride, tin chloride .or titanium chloride. substances, which are added in small amounts,

may be called accelerators. Suitable accelerators The aforesaid phenol, cresol, and monohydric aliphatic, cycloaliphatic or aromatic alcohols. Suitable alcohols are for example methanol,- ethyl alcohol. isobutyl alcohol, octyl alcohol, cyclohexanol, and benzyl alcohol.

. The favourable action of these accelerators results either in products having a higher molecular weight being formed, or in the reaction proceeding more rapidly than without the said additions, or in the possibility of carrying through the polymerization by means oi considerably smaller amounts of the catalysts oi the Friedel- Crafts reaction. In many cases several of these advantages are attained at the same time. Generally speaking, it is observed that the course of the polymerization can be controlled in a much better manner than hitherto in that the resulting polymerization products do not contain any substantial amounts of unalteredinltial materials 7 .depends on the reaction conditions and on the additional substance selected. Amounts of 0.01 per cent or slightly more are often sufiicient. Also in the production of interpolymerization products of isobutylene and dioleflnes amounts of less than 0.5 per cent are often sufficient, but it may be of advantage, as for example when using cyclohexanol as the accelerator, to use somewhat larger amounts, as for example up to 1 per cent.

When producing interpolymerization products of isobutylene and dioleflnes such dioleflnes are preferably used as have conjugated double linkages, as ior example butadiene, isoprene, dimethylbutadiene or chlorbutadiene. The relative proportions of isobutylene and dioleflne may be selected according to the desired properties of the finished product. As a rule it is preferable not to employ too'large an amount of dioleflnes. It is advantageous to work with from 5 to 40 parts by weight 01' dioleflne to from 95 to parts or isobutylene."

The interpolymerization products obtained may, like rubber, be vulcanized. After vulcanization they have extraordinarily high strength and are equal in this respect to the high molecular polymerization products 01 isobutylene alone, even when their molecular weight is considerably lower, or they are even superior to the iscbutylene polymerization products.

The following examples will further illustrate how the present invention may be carried out in practice, but the invention is not restricted to these aramples. Th partsare by volume unless otherwise stated.

Example 1 Reaction time Molecular weight 97, 0%

' 0.3 Del' cent of ethanol:

merized in the manner specified in Example 1, but with the addition of ethyl alcohol, the following results are obtained:

Parts oi gaseous boron fluoride 28 0 per cent of ethanol:

Molecular weight 102, 000 106,

'fi lggh i ly 104.000 1 o arwcg 000 220 000 200 Reaction time 06 36 12 0.05 r cent of ethanol:

olecnlar weight 100,

Reaction time 0.1 per cent 0! ethanol:

176, 000 H), 176, M) a) 5 Reaction timo- .IIIIIIIIIII Molecular weight 121,

173, 000 100, Reaction time 21 Example 3 Pure isobutylene is prepared as described in Example 1 and polymerized as therein described,

Parts oi gaseous boron fiuoride 28 00 100 160 0 per cent of isobutyl alcohol:

Molecular weight 95, 000 235, 000 88, Oil) 240, 000 Reaction time in seconds Abt. 400 250 130 60 0.01 per cent of isobntyl alcohol:

Molecular weight 284, 000 290, 000 274, 000 252, 000 Reaction time in seconds 90 00 30 i fil Ming] m0. 000 ms, 000 280 000 250, 000

, 0 or we g Reaction time in seconds so 20 1s 0.3 per cent of lsobutyl alcohol:

Moleailar wei ht 286, 000 283, 000 278, 000 265, 000 Reaction time seconds 15 13 I 0.6 per cent of isobutyl alcohol:

Molecular weight 248, 000 215, 000 270. 000 M7, 000 Reaction time in seconds .Abt. 10 Aht. 8 Not mea- Not meacurable curable By working in the same way with methanol, the results given in the following table are obtained:

Industrial isobutyl alcohol is converted by splitting oil water intoisobutylene and the latter purified by cautious distillation. If it be poly- 0 per cent of benzyl alcohol:

benzyl or octyl alcohol being used as the additional substance. The results are given below:

Parts oi gaseous boron fluoride 20 40 Molecular weight Reaction time (seconds) 0.1 per cent of bcnzyl alcohol:

Molecular weight Reaction time (seconds) 0.2 per cent oi benzyl alcohol;

Molecular weight Reaction time (seconds).

0 cent oi 1 alcohol:

lvic 20 ght Reaction time (seconds) 0.01 cent oi octyl alcohol: fi lecular weight Reaction time (seconds) 0.03 rlcent oi octyl alcohol:

ecular weight Reaction time (seconds) Mom 22 Example I action times determined when 30 parts of gaseous Isobutyl alcohol boiling at from 104- to 100- 0. Egg}??? {f f the Polymerizationls dehydrated, the resulting crude isobutylene disu tilled and then polymerized in the manner de- 5 scribed in Example 1 with the addition of cyclo- Mien hexanol. The results are as follows: Adam 3:13

fimg 20 40' 00 120 100 Without 011111010110);

0 per cent oi cyclohexanol:

Molecular weight- 205,000 210,000 104,000 110,000 102,000 Reaction time 140 100 50 25 2! 0.011 per1 cent 0! cyclo- X8n0 10101001110: woight.... 250,000 240,000 200,000 100.000 100.000 Example 7 Rmmmtime m M 10 Fur b tyl is btain db 11am 1! e1so u ene o e ysp go wai uifitlf ter from isobutyl alcohol boiling at from 105 to i s r lg e nsrwei han- 204,000 240,000 220,000 101,000 110,000 109 C. and distilling the resulting isobutylene.

on time 70 18 12 8 2o 20 parts oi the liquid isobutylene obtained are 0.1 1 5 eenc oi cyclomixed with from 40 to 60 parts of liquid ethylene nMoleaulariweightu- 254,000 235,000 220,000 212,000 200,000 and polymerized at 103 below zero 0. with the 7 amounts of boron fluoride given below with an 1, 535 9 addition of the specifled amounts of caproic acid.

Molecplm. weigmnu 24s 0o0 252,000 214,000 203,000 mom 25 The reaction time in seconds (r. t.) and the mo- Reflcmn time- 24 10 7 5 lecular weights (in. w.) of the polymerization products are given in the following table:

Percentage oi ceproic acid added Partsoignseous boron 0 0.01 0.03 0.06 0.1

fluoride DLW. Lt. Ill-W. ht. IIL'. Lt. HLW. Lt. IJLW. r. 1;.

Example 5 40 Example 8 Pure isobutylene is polymerized as described in Example 1 but with an addition of phenol. In order to obtain the same reaction time it is only necessary to use when adding phenol about one, tenth to one fifteenth of the amount of catalyst which must be used for polymerization without the addition of phenol, as may be seen from the following table:

Example 6 Instead of the phenol used in Example 5, the

compounds specified below are added and the re- A mixture of grams of liquid isobutylene to which 0.05 per cent of isobutyl alcohol has been added, and 20 grams of liquid butadiene is cooled to 103 below zero C. with 200 grams of liquid ethylene. A solution of cubic centimeters of gaseous boron fluoride in about 50 cubic centimeters of liquid ethylene is then poured in. The reaction commences immediately and is mainly completed after about 500 seconds. The polymerization product obtained then immediately has methanol poured thereover in order to render any boron fluoride still present inactive. After removing the alcohol and ethylene, an interpolymerization product having a molecular weight of 20,000 is obtained.

By working under the same conditions, but without an addition of isobutyl alcohol, aninterpolymerization product is obtained having a molecular weight of 14,000.

Example 9 A mixture of 320 grams of liquid isobutylene to which 0.1 per cent of isobutyl alcohol has been added, 80 grams oi liquid butadiene and 600 grams of liquid ethylene is cooled to from about to below zero C. by pouring liquid methane therein. There are then poured in consecutively two batches each of 400 cubic centimeters of gaseous boron fluoride dissolved in about 50 cubic centimeters of liquid ethylene. The main reaction is completed after from about 4 to 5 minutes; methanol is then poured over and the alcohol, ethylene and methane removed. The interpolymerization product has a molecular weight of 68,000.

Instead of methane, ethylene alone may be used for obtaining the low temperature in sucking the same oil under a vacuum or from about 50 to 100 millimeters (mercury gauge) From the resulting interpolymerization product, the following mixture is prepared at 160 C. on the rollers:

The mixture is vulcanized for 90 minutes at 150 C. The vulcanizate thus prepared has astrength of 166 kilograms per square centimeter, an extension of 935 per cent, a recoil elasticity of 12 and a Shore hardness of 65 at 20 C.

If the polymerization be carried out without an addition of isobutyl alcohol, there is obtained with two batches each of 480 cubic centimeters of gaseous boron, fluoride under otherwise the same conditions an lnterpolymerization product having a molecular weight of 31,500.

By using 1 per cent or cyclohexanol in the polymerization instead of isobutyl alcohol under the same conditions, an interpolymerization product is obtained having a molecular weight of 37,000.

Example A mixture of 80 grams of liquid isobutylene to which 0.1 per cent of isobutyl alcohol has been added, and 20 grams of liquid butadiene is cooled by means of liquid methane to'between 130 and 140 below zero C. Thereafter a solution of 165 cubic centimeters of gaseous boron fluoride dissolved in 100 cubic centimeters of liquid methane is slowly added. The reaction is complete after about 3 minutes. The resulting p lymerizate is treated with methanol in order to destroy any boron fluoride still present. The product is then subjected to a rolling treatment while treating it with hot water whereby the alcohol and occluded gases areremoved. An interpolymerlza-' tion product having a molecular weight of 150,000 is obtained.

v Example 11 When varying in the process of the foregoing example the proportions of isobutylene and butadiene mixed polymerizates are obtained which have the molecular weights and, after vulcanization, the strength values indicated in the following table. For carrying through the vulcanization the interpolymerizates are first dried at 120 C. in a kneading or rolling machine. Thereafter at 140 C. 100 parts by weight of the interpolymerization product are mixed by rolling with 40 parts 01' gas black, 5 parts of zinc oxide, 3 parts of sulphur and 3 parts oi. stearic acid during 20 minutes. The mass is then allowed to cool to about 80 C. and mixed at that temperature with 3 parts of mercaptobenzothiazole and 1 part of tetramethylthiuramdisulflde. The vulcanization is then eflected by heating for minutes to 155' C.

M leoulsr Extend 0 mm or B 0n Pro rtionoi weight of looting an exi gf n the iso utylene polymerizatension to moment of tobutadiene tion prodfa rupture in not an a per cent 75225 100,000 41 109 207 720 70130 615m 13 o 35 184 907 67233 100.000 53 134 183 621 60:40 20 54 184 861 50250 80, M 66 171 521 What I claim is:

1. The process of producing polymerization products which comprises contacting a liquid containing a member oi the group consisting of isobutylene and mixtures 01 a major portion of isobutylene and a minor portion of an olefinic compound having conjugated double bonds to which liquid there has been addeda polymerization-promoting amount of up to 1% based on the isobutylene present 01' a compound which is so]- uble in the reaction mixture under the reaction conditions and capable oi. dissolving boron fluoride, said compound being selected from the group consisting of monohydrie alcohols, phenol and cresol with a Friedel-Crafts reaction catalyst at a temperature below 10 C. 1

2. The process as claimed'in claim 1 in which v the liquid treated is liquid isobutylene.

3. The process as claimed in claim 1 in which the liquid treated essentially comprises isobutylene and a dioleflne. I

4. The process as claimed in claim ,1 in which the liquid treated essentially comprises isobutylene and butadiene.

5. The process as claimed in claim 1 in which the added substance is a monoh dric alcohol.

6. The process as claimed in claim 1 inwhich the added substance is a monohydric aliphatic alcohol.

'1. The process as claimed in claim 1 in which the liquid treated is liquid isobutylene and the added substance is a monohydric aliphatic a1- cohol. v

8. The process as claimed in claim 1 in which the liquid treated essentially comprises isobutylene and butadiene and the added substance is a monohydric aliphatic alcohol.

MICHAEL OTTO. 

